Somalias al-Shabaab has claimed responsibility for an attack in which a US commando was killed and four others were wounded when they came under fire in the country. The US special operations forces were fighting alongside about 800 troops from the Somali National Security Forces and Kenyan Defense Forces when they were attacked late on Friday by mortars and small arms fire. "We attacked a military base ... killed one US soldier, two Kenyan soldiers and nine Somali soldiers from Jubbaland state. We also injured four US soldiers," Abdiasis Abu Musab, al-Shabaab’s military operations spokesman, told Reuters late Friday. He said the attack was in the southern town of Kismayo. In a statement, the US military said on Friday one local soldier was also wounded in the attack that also involved Somali and Kenyan forces. The troops had been on a mission to clear al-Shabaab from contested areas as well as villages the militants controlled, "and establish a permanent combat outpost" to expand the reach of the Somali state, according to the US statement. Kenyan military spokesman David Obonyo told Reuters that its forces were not involved in any operations in Somalia on Friday. About 500 US troops are deployed in Somalia. Meanwhile, the US militarys Africa Command on Friday dismissed allegations that a Somali-led raid conducted with US assistance had resulted in the deaths of civilians. US forces, in an advise-and-assist capacity, partnered with Somali forces in a raid targeting Ial-Qaeda militants aligned with al-Shabaab on May 9. According to AFP, Ali Mohamed Moalin, a traditional elder who lives close to Afgoye in Lower Shabelle where the raid took place, said five "innocent farmers" were killed. AFRICOM said it had conducted a thorough review of the case. We "determined the allegations of civilian casualties to be not credible," officials said in a statement. "As with any allegation of civilian casualties, US Africa Command reviewed all available relevant information concerning the incident."